According to the Cleveland Clinic, which is considered one of the
world's top hospitals, there's an easy way to find a healthy
sitting position. It involves four basic steps that, assuming
you're reading this on a tablet, phone, or computer screen, you
can try right now:

First, sit at the end of your chair (that's right, don't rely on
your backrest). Let your body go into a slouching position. Now,
try to sit up straight, accentuating the curve of your back as
much as possible. Hold this position for a few seconds. Next,
release the position a little bit — Cleveland specifies that you
shouldn't move more than about 10 degrees. This should be your
sitting position!

Now that you've got it, make sure the rest of your body is in the
proper alignment to ensure you're not cutting off your
circulation or straining any other joints.

Make sure your body weight is evenly distributed across your
seat. Then, check your knee position. They should be bent at
roughly a right angle, uncrossed, with your feet flat on the
floor.

If you're in an office, you can adjust your chair height and desk
so that you sit fairly close to your screen. Your elbows and arms
should rest either on your desk or your chair's armrests, and
your shoulders should be relaxed. If you're on a rolling chair,
you should avoid twisting at the waist and pivot your whole body
instead,
the Clinic adds.

Doing this every day will help protect your joints, ligaments,
bones, and muscles, and can also help you feel
more energized throughout the day, since your muscles are
being used more efficiently.